Shelfari is a very nice alternative to the Amazon discussion forums. It’s a lot like Goodreads but nicer looking and a little less confusing.
You will find information about books and authors as well as promotions sponsored by Amazon. What’s unique about Shelfari is the ability for users to add information about their favorite books. In fact a number of authors add bonus material to the Shelfari entry for their books.
I would recommend stopping by and taking a look around. If you have an Amazon account, you can use it to log into Shelfari.